Hello.

I'd like to have my prompt alert me when I have staged changes (because it's a
pain to keep running 'git diff --staged' before every 'git commit -a').
However, I don't want to enable detection of unstaged changes too as that's
more expensive (disk crawl v. metadata crawl).

Put another way, I want to have %c/stagedstr without the cost of %u/unstagestr.

The current code makes detection of %u,%c an all-or-nothing deal:

    # excerpt from Functions/VCS_Info/Backends/VCS_INFO_get_data_git
    if zstyle -t ":vcs_info:${vcs}:${usercontext}:${rrn}" "check-for-changes" && ... ; then
        # Default: off - these are potentially expensive on big repositories
        ${vcs_comm[cmd]} diff --no-ext-diff --ignore-submodules --quiet --exit-code ||
            gitunstaged=1
        ${vcs_comm[cmd]} diff-index --cached --quiet --ignore-submodules HEAD 2> /dev/null
        (( $? && $? != 128 )) && gitstaged=1
    fi

I went ahead and implemented a way to enable %c without %u, specifically by
adding a 'check-for-staged-changes' style that sets %c but not %u and leaving
'check-for-changes' unchanged (sets both %c and %u).  See attached patch.

WDYT?

Daniel

---

Recipe for testing:

zsh -f
cd $MY_ZSH_SOURCE_DIR
zstyle ':vcs_info:git:*' stagedstr '[+]'
zstyle ':vcs_info:git:*' check-for-staged-changes true
zstyle ':vcs_info:git:*' formats '%b%c'
fpath=( $PWD/Functions/**/*(/) )
autoload -Uz vcs_info
_precmd_vcs_info() { vcs_info; print -P ${vcs_info_msg_0_} }
precmd_functions+=(_precmd_vcs_info)
git rm --quiet -- README
git checkout HEAD -- README
# Observe the last two prompts.